Grinding tool for buttons of a rock drill bit

ABSTRACT

The present invention provides a grinding cup ( 31 ) having a lower grinding section ( 32 ) and an upper body section ( 33 ) connected to form a grinding cup having top ( 34 ) and bottom surfaces ( 35 ). The grinding section ( 32 ) is formed from a material capable of grinding the hard materials such as tungsten carbide inserts of button bits etc. A centrally disposed convex recess is formed in the bottom surface ( 35 ) having the desired size and profile for the button to be ground. Drive means ( 38 ) are provided on or in the upper body section that cooperate with the output shaft of the grinding machine. The drive means ( 38 ) and the upper body section or grinding section ( 33 ) of the grinding cup are adapted to optimize the engagement surfaces and points of contact between the grinding cup ( 31 ) and rotor or adapter to reduce negative impact on operational stability and rotor wear, as well as other potential associated wear to the grinding apparatus caused by vibration and/or resonance.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to improvements in devices for useas grinding cups for grinding the hard metal inserts or working tips ofdrill bits (percussive or rotary), tunnel boring machine cutters (TBM)and raised bore machine cutters (RBM) and more specifically, but notexclusively, for grinding the tungsten carbide cutting teeth or buttonsof a drill bit or cutter and the means for detachably connecting thegrinding cups to the grinding machine.

[0002] In drilling operations the cutting teeth (buttons) on the drillbits or cutters become flattened (worn) after continued use. Regularmaintenance of the drill bit or cutter by regrinding (sharpening) thebuttons to restore them to substantially their original profile enhancesthe bit/cutter life, speeds up drilling and reduces drilling costs.Regrinding should be undertaken when the wear of the buttons isoptimally one third to a maximum of one-half the button diameter.

[0003] Different manual and semi-automatic grinding machines are knownfor grinding button bits/cutters (see for example U.S. Pat. Nos.5,193,312; 5,070,654). In a conventional type of machine a grinding cuphaving the desired profile is rotated at high speed to grind the carbidebutton and the face of the bit/cutter surrounding the base of the buttonto restore the button to substantially its original profile foreffective drilling.

[0004] The grinding cups conventionally consist of a cylindrical bodyhaving top and bottom surfaces. The bottom or working surface consistsof a diamond/metal matrix having a centrally disposed convex recesshaving the desired profile for the button to be ground. A beveled rimaround the recess removes steel from the face of the bit around the baseof the button.

[0005] Water and/or air, optionally with some form of cutting oil, isprovided to the grinding surface to flush and cool the surface of thebutton during grinding.

[0006] The grinding cups are provided in different sizes and profiles tomatch the standard sizes and profiles of the buttons on the drill bitsor cutters. Typically the button diameter varies from 6 mm up to 26 mm.

[0007] The grinding cups are conventionally manufactured by firstmachining a blank. The blank is then pressed into a mould containing ahot diamond/metal mixture. The bottom surface of the blank is heated andbonds to the diamond/metal matrix. Alternatively the diamond/metalmatrix can be formed into the grinding section and then bonded either bya shrink fit and/or with adhesives or solder to a blank.

[0008] Several different methods are used to connect and retain thegrinding cups on to the grinding machine. The grinding cups wereconventionally held in the grinding machine by inserting an uprighthollow stem projecting from the top surface of the grinding cup into achuck for detachable mounting of tools. Special tools such as chuckwrenches, nuts and collets are necessary to insert, hold and to removethe grinding cup into and out of the chuck.

[0009] To eliminate the need for chuck wrenches etc. the use of ashoulder drive on the grinding cups was developed. A diametricallyextending recess at the free end of a hollow drive shaft of the grindingmachine cooperates with a shoulder or cam means on the adjacent topsurface of the grinding cup. The stem of the grinding cup is insertedinto the hollow drive shaft and maybe held in place by one or moreO-rings either located in a groove in the interior wall of the driveshaft or on the stem of the grinding cup. See for example Swedish PatentNo. B 460,584 and U.S. Pat. No. 5,527,206.

[0010] An alternative to the shoulder drive is that shown, for example,in Uniroc AB's Canadian Patent 2,136,998. The free end of the stem ofthe grinding cup is machined to provide flat drive surfaces on the stemthat are inserted into a corresponding drive part in the channel of theoutput drive shaft into which the stem is inserted. The grinding cup isretained in place by a spring biased sleeve which forces balls mountedin the wall of the output drive shaft into an annular groove on the stemof the grinding cup.

[0011] Recent innovations are illustrated in U.S. Pat. No. 5,639,273 andU.S. Pat. No. 5,727,994. In these patents, the upright stem has beenreplaced with a centrally disposed cavity provided in the top surface ofthe grinding cup. The cavity is shaped and sized to permit the outputdrive shaft of a grinding machine to be inserted into the cavity.

[0012] Some manufacturers, in order to provide grinding cups that arecompatible for use with other manufacturers grinding machines provideadapters that connect their grinding cup to the output drive shaft ofcompetitors grinding machines.

[0013] Regardless of the method of connecting the grinding cup to theoutput drive shaft of the grinding machine, the present invention hasdetermined that it is important to optimize the operational stability ofthe grinding cup. Lack of operational stability often results invibration and resonance during grinding. Vibration and/or resonance alsodirectly results in increased rates of wear to all moving parts such asbearings, joints, etc. of the grinding apparatus and can potentiallyinterfere with settings within the operating control circuits of thegrinding apparatus. In addition, lack of operational stability resultsin increased wear to all key drive/contact surfaces of the output driveshaft (rotor) and grinding cup which provide consistent, properalignment between grinding cup and or adapter and the rotor duringoperation. Operational instability and associated vibration and/orresonance is a major contributor to the deterioration of the preferredbuilt-in profile of the cavity in the grinding section of the grindingcup. This directly results in a deterioration in the profile of therestored button. The net effect being a substantial loss in the intendedoverall drilling performance of the drill bit or cutter used.

[0014] In addition, due to the fact that most grinding cup designs aresized relative to the size and profile of the button to be ground, somegrinding cups have protruding and/or irregular features even whenengaged. with the drive means of the rotor and/or adapter. Othergrinding cups, such as those of smaller size, without protrudingfeatures, once engaged with the drive means of the rotor, often resultin relatively sharp and/or protruding features of the drive means of therotor being exposed. Some efforts have been made in conventionalgrinding cups to round off exposed edges on the drive means of grindingcups in an attempt to reduce operator exposure to sharp features. Theseefforts however have not eliminated the problem of protruding and/orirregular features, but rather attempted to lessen their impact.

SUMMARY OF THE INVENTION

[0015] It is an object of the present invention to optimize theengagement surfaces and/or points of contact on the drive means of agrinding cup relative to the corresponding drive and/or contact surfacesof the grinding apparatus rotor or adapter to prevent uneven wear andreduce vibration.

[0016] It is a further object of the present invention to reducenegative impact on operational stability, drive/contact surfacewear/damage, wear/damage and/or deformation of elastomeric materials inthe drive and/or contact areas, as well as other potential associatedwear/damage to the grinding apparatus caused by vibration and/orresonance

[0017] It is a further object of the present invention to improveoperational stability by optimizing/harmonizing the forces transferredbetween the rotor and grinding cup or grinding cup and adapter oradapter and rotor during operation including torsion (rotational)forces, axial (feed) forces and radial (varying side load) forces.

[0018] It is a further object of the present invention to minimizeoperator exposure to sharp and/or protruding features when the grindingcup and rotor have engaged.

[0019] It is a further object of the present invention to substantiallystreamline/harmonize all contact surfaces including the combined outsidegeometry at the transition point between grinding cups androtor/adapter.

[0020] Accordingly the present invention provides a grinding cup havinga lower grinding section and an upper body section connected to form agrinding cup having top and bottom surfaces. Drive means are provided onor in the upper body section that cooperate with the output shaft of thegrinding machine. Retaining means are provided in conjunction with thedrive means to releasably secure the grinding cup, directly orindirectly with an adapter, to the output shaft of the grinding machineduring use. The drive means or upper body section are adapted to reducenegative impact on operational stability, drive/contact surfacewear/damage, wear/damage and/or deformation of elastomeric materials inthe drive and/or contact areas, as well as other potential associatedwear/damage to the grinding apparatus caused by vibration and/orresonance. In addition, substantially reducing vibration and/orresonance will minimize the deterioration of the preferred built-inprofile of the cavity in the grinding section. In the preferred designthe drive and/or contact surfaces between grinding cup and rotor oradapter are substantially harmonized, minimizing operator exposure tosharp and/or protruding features when the grinding cup and rotor haveengaged.

[0021] Another aspect of the present invention provides an adapter forreleasably connecting a grinding cup to the output shaft of the grindingapparatus. The adapter consists of a holder portion for detachableconnection to a grinding cup and a connector portion for releaseableconnection to the output shaft of a grinding machine. The holder portionand/or connector portion are adapted to reduce negative impact onoperational stability, drive/contact surface wear/damage, wear/damageand/or deformation of elastomeric materials in the drive and/or contactareas, as well as other potential associated wear/damage to the grindingapparatus caused by vibration and/or resonance. In the preferred designthe drive and/or contact surfaces between adapter and output shaft orgrinding cup are substantially harmonized, minimizing operator exposureto sharp and/or protruding features when the grinding cup and rotor haveengaged.

[0022] Further features of the invention will be described or willbecome apparent in the course of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order that the invention may be more clearly understood, thepreferred embodiment thereof will now be described in detail by way ofexample, with reference to the accompanying drawings, in which:

[0024]FIG. 1 is a side elevation partly in section of a grinding machinehaving a single air motor, the rotor of which is adapted to retain agrinding cup having a shoulder drive;

[0025]FIG. 2 is a bottom view of the rotor seen in the direction of theline A-A in FIG. 1; and

[0026]FIG. 3 is an enlarged perspective view of an embodiment of ashoulder drive grinding cup according to the present invention forgrinding larger sizes of buttons;

[0027]FIG. 4 is a top plan view of the grinding cup of FIG. 3.

[0028]FIG. 5 is a cross section of the grinding cup of FIG. 3 along 5-5.

[0029]FIG. 6 is a bottom plan view of the grinding cup of FIG. 3.

[0030]FIG. 7 is an enlarged perspective view of another grinding cupaccording to the invention for grinding small button bits.

[0031]FIG. 8 is a top plan view of the grinding cup of FIG. 7.

[0032]FIG. 9 is a cross section of the grinding cup of FIG. 8 along 9-9.

[0033]FIG. 10 is a bottom plan view of the grinding cup of FIG. 7.

[0034]FIG. 11 is a cross-sectional view of an adapter according to theinvention.

[0035]FIG. 12 is a cross-sectional view of another embodiment of anadapter according to the present invention.

[0036]FIG. 13 is an enlarged perspective view of another embodiment of agrinding cup according to the invention.

[0037]FIG. 14 is a longitudinal cross section of extended form ofadapter according to the present invention.

[0038]FIG. 15 is a longitudinal cross section of another embodiment of agrinding cup according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0039] The present invention is best illustrated in conjunction withgrinding cups utilizing a shoulder drive but is also applicable to othertypes of drive means on grinding cups or with the use of adapters toconnect a grinding cup with one type of drive means to the output driveshaft of a grinding machine having a different type of drive system.FIGS. 1 and 2 show a grinding machine 10 which includes a motor housingor casing 12 within which is suitably supported a rotary motor, theillustrated motor being a pneumatically driven motor 14 adapted to besupplied with compressed air from a suitable source (not shown). Thedimensions of the casing 12 are such that the grinding machine may beeasily handled manually. It is understood that the present inventionalso has application for use with automatic and semi-automatic grindingmachines, such as those disclosed in U.S. Pat. No. 5,193,312, the manualheld machine being illustrated for convenience. The casing is providedwith handles 16 projecting outwardly from the casing in a manner thatprovides maximized ergonomics to the operator. The motor 14 drives anoutput shaft 18. Suitably connected to the output shaft 18 by anyconventional means is a holder device 20 into or onto which the grindingcup or adapter/grinding cup combination may be engaged. In theillustrated embodiment, the holder device 20 is an integral extension ofthe shaft 18 which constitutes an elongate member. The holder devicecould also consist of either a separate attachment to the output shaftof the rotor or an adapter to connect a grinding cup having one type ofdrive means to an output drive shaft having a different type of drivemeans. For example the adapter could connect a shoulder drive grindingcup to a different output drive shaft such as the hex drive system asillustrated in U.S. Pat. No. 5,639,273 or U.S. Pat. No. 5,727,994 or thedrive system illustrated in Canadian Patent 2,136,998. In the device asshown, the shaft 18 and holder device 20 are provided with a coaxialpassageway or opening 22 extending the length thereof and through whichcoolant fluid may be directed to a grinding cup to be supported thereon.An outer portion 24 of the opening 22, extending inwardly from a freeend 26 of the holder device 20, is sized snugly, but slidably, toreceive a stem of the grinding cup. Interengaging means 27 are providedon the holder device 20 to engage and rotate a grinding cup when in use.In the grinding machine 10 illustrated, the interengaging means 27consists of a diametrically extending slot 28 in the free end 26 of theoutput shaft 18. The slot 28 has a top wall 29 and dependingsubstantially parallel side walls 30. The top wall 29 and side walls 30comprise the drive or contact surfaces on the holder device.

[0040] The grinding cups of the present invention have a number offeatures directed to (1) optimizing the drive surface on the drive meansto prevent uneven wear and further reduce vibration to optimize thedrive and/or contact surfaces on the drive means of a grinding cuprelative to the corresponding drive and/or contact surfaces of thegrinding apparatus rotor/adapter to prevent uneven wear and reducevibration (2) reduce negative impact on wear/damage and/or deformationof elastomeric materials in drive and/or contact areas (3) improvingoperational stability by optimizing/harmonizing the forces transferredbetween the rotor and grinding cup during operation including torsion(rotational) forces, axial (feed) forces and radial (varying side load)forces (4) minimizing operator exposure to sharp and/or protrudingfeatures when the grinding cup and rotor have engaged (5) substantiallystreamline/harmonize all contact surfaces including the combined outsidegeometry at the transition point between grinding cups and rotor/adapterand (6) standardizing components, wherever practical, regardless of thesize of the button to be ground to reduce manufacturing costs.

[0041] Referring to FIGS. 3-6, one embodiment of a grinding cupaccording to the present invention is generally indicated at 31. Thegrinding cup 31 is for use with a grinding machine of the typeillustrated in FIGS. 1-2, which incorporates a diametrically extendingslot 28 at the free end 26 of the output drive shaft 18 that cooperateswith a shoulder or cam means on the adjacent top surface of the grindingcup such as described in U.S. Pat. No. 5,527,206. The grinding cup 31consists of a lower grinding section 32 and an upper body section 33connected to form a grinding cup having top and bottom surfaces 34 and35 respectively. The grinding section 32 is formed from a materialcapable of grinding the tungsten carbide inserts of button bits. In thepreferred embodiment, the grinding section is formed from a metal anddiamond matrix. The peripheral edge 36 in the bottom surface 35 ispreferably beveled to facilitate the removal of steel from the face ofthe bit around the base of the button during grinding. A centrallydisposed convex recess 37 is formed in the bottom surface 35 having thedesired size and profile for the button to be ground.

[0042] Drive means 38 are provided on or in the upper body section 33that cooperate with the output shaft of the grinding machine. In FIGS.3-6, the drive means 38 consists of a hollow vertical upright stem 39centrally located on the top surface 34 of the grinding cup 31. Cammeans or shoulder 40 is provided at the base of the stem 39 and is sizedto engage with the diametrically extending slot 28 at the free end 26 ofthe output drive shaft 18 of the grinding machine 10 (see FIGS. 1-2).The cam 40 has an upper surface 41, parallel side walls 42 and end walls43. The hollow stem 39 is inserted into the outer portion 24 of theopening 22 in the holder device 20 of the grinding machine 10. Retainingmeans 44 are provided in conjunction with the drive means 38 toreleasably secure the grinding cup to the output shaft of the grindingmachine during use. In the preferred embodiment illustrated in FIGS.3-6, the retaining means 44 are one or more O-rings 45 located in one ormore grooves 46 on the stem 39 of the grinding cup. Optionally theretaining means could also be located on the output drive shaft or acombination on both the grinding cup and the drive shaft workingindependently or cooperatively. The passageway 47 in stem 39 connects toa corresponding passageway 48 in the body section 33 and grindingsection 32 to permit a coolant, preferably water, optionally mixed withcutting oil or a water/air mist, to be provided to the surface of thebutton during grinding, through one or more outlets 49. As shown in FIG.6, the outlets 49 in this embodiment consist of three slots 50,51,52radially extending from the centre 53 of the convex recess 37. Thecoolant prevents excessive heat generation during grinding and flushesthe surface of the button of material removed during grinding. Inaddition, the diameter of the passageway 48 adjacent to outlets 50-52may be expanded to facilitate optimized flow between passageway andoutlets.

[0043] In the embodiment shown, the drive means 38, upper body section33 and grinding section 32 of the grinding cup 31 are adapted tooptimize contact between the engagement surfaces (top surface 41 andside walls 42 of cam 40) on the drive means of the grinding cup and thecorresponding engagement surfaces (top wall 29 and side walls 30 of slot28) on the output drive shaft of the grinding machine to reducevibration to reduce rotor wear, as well as other potential associatedwear to the grinding apparatus caused by vibration and/or resonance andto improve operational stability by optimizing and harmonizing theforces transferred between the rotor/adapter and grinding cup duringoperation including torsion (rotational) forces, axial (feed) forces andradial (varying side load) forces and to reduce negative impact onoperational stability, drive/contact surface wear/damage, wear/damageand/or deformation of elastomeric materials in the drive and/or contactareas.

[0044] In the embodiment shown, cam means or shoulder 40 provided at thebase of the stem 39 is sized and shaped so that the engagement surfaceson said cam or shoulder are optimized to and match with thecorresponding engagement surfaces of slot 28. In addition the cam orshoulder 40 is preferably substantially the substantially the samelength, width and depth as the diametrically extending slot 28 at thefree end 26 of the output drive shaft 18 of the grinding machine. Thisoptimizes the contact area between the top wall 29 and side walls 30 ofslot 28 on the drive shaft and the top surface 41 and side walls 42 ofthe cam 40 on the grinding cup resulting in reduced vibration and rotorwear, as well as other potential associated wear to the grindingapparatus caused by vibration and/or resonance. Reduced vibration alsoimproves operational stability, drive/contact surface wear/damage,wear/damage and/or deformation of elastomeric materials in the driveand/or contact areas by optimizing and harmonizing the forcestransferred between the rotor and grinding cup during operationincluding torsion (rotational) forces, axial (feed) forces and radial(varying side load) forces. In addition, substantially reducingvibration and/or resonance, minimizes the deterioration of the preferredbuilt-in profile of the cavity in the grinding section.

[0045] Standardizing components, wherever practical, regardless of thesize of the button to be ground will reduce manufacturing costs andminimize operator exposure to sharp and/or protruding features when thegrinding cup and rotor have engaged. In the embodiment illustrated, thediameter D of the top surface 34 of the upper body section 33 and thelength D of the cam 40 between end walls 43 is about the same as thelength of the diametrically extending slot 28 at the free end 26 of theoutput drive shaft 18 of the grinding machine. This avoids any sharp orprotruding surfaces. In some cases it may be appropriate to have theexterior surface of the free end 26 of the output drive shaft 18 in thevicinity of slot 28 be tapered to further eliminate sharp and/orprotruding surfaces while improving accessibility to the grinding cupfor faster and easier switching to appropriate size and profile ofgrinding cup. To optimize and harmonize the various loads such astorsion loads and resulting operational loads such as radial and axialloads over a range of various sizes and profiles of grinding cups, thecam or shoulder may be sized differently in relation to thediametrically extending slot at the free end of the output drive shaftor adaptor if one is being used. In the embodiment shown, because of thesize of the tool, the upper body section 33 has a constant diameterthroughout its length to the point of contact 55 with the grindingsection 32.

[0046] To accommodate the diameter of the upper body section 33 relativeto the size of the button to be ground, the peripheral surface 56 of themetal portion 57 of grinding section 32 is machined to the point ofconnection 55 with the upper body section 33 in a profile preferablycorresponding to the diamond matrix 58. The thickness T of the metalportion 57 of the grinding section 32 in the area should be sufficientto provide structural support for the diamond matrix 58.

[0047] The above noted methods to optimize the contact area between thedrive shaft and the grinding cup and standardize components, whereverpractical, regardless of the size of the button to be ground will reducemanufacturing costs and minimize operator exposure to sharp and/orprotruding features when the grinding cup and rotor have engaged. Inaddition, this results in less vibration to reduce rotor wear, as wellas other potential associated wear to the grinding apparatus caused byvibration and/or resonance and reduces negative impact on operationalstability, drive/contact surface wear/damage, wear/damage and/ordeformation of elastomeric materials in the drive and/or contact areasby optimizing and harmonizing the forces transferred between the rotorand grinding cup during operation including torsion (rotational) forces,axial (feed) forces and radial (varying side load) forces. In addition,deterioration of the preferred built-in profile of the cavity in thegrinding section is minimized. Consideration is given to the size of thegrinding cup, the drive means selected, manufacturing costs, areasrequired for product identification and necessary structural strengthand/or support in implementation of the present invention. The presentinvention does not require in each case all of the possible methods tobe employed. Either the drive means and the upper body section orgrinding section may be adapted or any combination thereof. Further theinvention is applicable to all types of grinding cups regardless of themeans used to drive, connect and retain the grinding cup on the grindingmachine. The invention is applicable regardless of whether the grindingcup is of the type having an upright hollow step for insertion into achuck, has a shoulder drive as shown in FIGS. 3-6, is of the typeillustrated in U.S. Pat. No. 5,688,163 where the free end of the stem ismachined to provide the drive surfaces or is of the type illustrated inU.S. Pat. Nos. 5,639,237 and 5,727,994 or is provided with an adapterthat connects one type of grinding cup to an output drive shaft having adifferent drive system or any modifications or improvements thereon.

[0048] FIGS. 7-10 illustrate the application of the present inventionwith a grinding cup 70 intended to grind small diameter buttons. Thegrinding cup 70 is for use with a grinding machine which incorporates adiametrically extending slot at the free end of a hollow drive shaftthat co-operates with a shoulder or cam means on the adjacent topsurface of the grinding cup such as described in U.S. Pat. No.5,527,206. The grinding cup 70 consists of a lower grinding section 71and an upper body section 72 connected to form a grinding cup having topand bottom surfaces 73 and 74 respectively. The grinding section 71 isformed from a material capable of grinding the tungsten carbide insertsof button bits. In the preferred embodiment, the grinding section isformed from a metal and diamond matrix. The peripheral edge 75 in thebottom surface 74 is preferably beveled to facilitate the removal ofsteel from the face of the bit around the base of the button duringgrinding. A centrally disposed convex recess 76 is formed in the bottomsurface 74 having the desired profile for the button to be ground.

[0049] Drive means 77 are provided on the upper body section 72 thatcooperate with the output drive shaft of the grinding machine. In FIGS.7-10, the drive means 77 consists of a hollow vertical upright stem 78centrally located on the top surface 73 of the grinding cup 70. Cammeans or shoulder 79, having a top surface 80, depending parallel sidewalls 81 and end walls 82, is provided at the base of the stem 78 and issized to engage with a diametrically extending slot 28 (FIG. 1) at thefree end 26 of an output drive shaft of the grinding machine. The hollowstem 78 is inserted into the opening 22 in the output drive shaft of thegrinding machine. Retaining means 83 are provided in conjunction withthe drive means 77 to releasably secure the grinding cup to the outputdrive shaft of the grinding machine during use. In the preferredembodiment illustrated in FIGS. 7-10, the retaining means 83 are one ormore O-rings 84 located in one or more grooves 85 on the stem 78 of thegrinding cup. Optionally the retaining means could also be located onthe drive shaft or a combination of retaining means located on both thegrinding cup and output drive shaft working independently orcooperatively.

[0050] The passageway 86 in stem 78 connects to a correspondingpassageway 87 in the body section 72 and grinding section 71 to permit acoolant, preferably water, optionally mixed with cutting oil or awater/air mist, to be provided to the surface of the button duringgrinding, through one or more outlets 88. In addition the diameter ofpassageway 87 adjacent to outlet 88 may be expanded to facilitateoptimized flow between passageway and outlets.

[0051] In the embodiment shown, the upper body section 72, grindingsection 71 and drive means 77 of the grinding cup 70 are adapted tooptimize the engagement surfaces (top surface 80 and side walls 81 ofcam 79) on the drive means of the grinding cup with the correspondingcontact surfaces (top wall 29 and side walls 30 of slot 28) on theoutput drive shaft to reduce vibration to thereby reduce rotor wear, aswell as other potential associated wear to the grinding apparatus causedby vibration and/or resonance and to improve operational stability byoptimizing and harmonizing the forces transferred between the rotor andgrinding cup during operation including torsion (rotational) forces,axial (feed) forces and radial (varying side load) forces.

[0052] Cam means or shoulder 79 provided at the base of the stem 78 ispreferably substantially the same size (height, width and length) as thediametrically extending slot at the free end of the output drive shaftof the grinding machine. This optimizes the contact area between theengaging surfaces on the drive shaft and the grinding cup resulting inreduced vibration and rotor wear, as well as other potential associatedwear to the grinding apparatus caused by vibration and/or resonance.Reduced vibration also improves operational stability, drive/contactsurface wear/damage, wear/damage and/or deformation of elastomericmaterials in the drive and/or contact areas by optimizing andharmonizing the forces transferred between the rotor and grinding cupduring operation including torsion (rotational) forces, axial (feed)forces and radial (varying side load) forces. In addition, substantiallyreducing vibration and/or resonance, minimizes the deterioration of thepreferred built-in profile of the cavity in the grinding section.

[0053] As noted previously, standardizing components, whereverpractical, regardless of the size of the button to be ground will reducemanufacturing costs and minimize operator exposure to sharp and/orprotruding features when the grinding cup and rotor have engaged. In theembodiment illustrated, the top surface 73 of the upper body section 72has a diameter D* about the same as the diameter of the diametricallyextending recess at the free end of the hollow drive shaft of thegrinding machine. To optimize and harmonize the various loads such astorsion loads and resulting operational loads such as radial and axialloads over a range of various sizes and profiles of grinding cups, thecam or shoulder may be sized differently in relation to thediametrically extending slot at the free end of the output drive shaftor adaptor if one is being used. In the grinding cup illustrated inFIGS. 7-10, the diameter of the body section 72 is reduced by taperingpart or all the exterior surface 89 of the upper body section to form abeveled portion 90. Alternatively the reduction of the diameter of theexterior surface 87 can be radial or form a reverse radius. The beveledportion 90 terminates in neck portion 91 that connects to the grindingsection 71. In the embodiment illustrated in FIGS. 7-10, neck portion 91is generally cylindrical with a diameter sufficient to providestructural support for the grinding cup 70.

[0054] The grinding section 71, in the embodiment illustrated in FIGS.7-10 does not have sufficient diameter to have its exterior surface 92machined in a profile corresponding to the diamond matrix 93 as in FIGS.3-6.

[0055] To optimize volume of coolant delivered to the grinding section71, the diameter of the passageways 86, 87 through the stem 78 andgrinding cup 70 is increased as wide as possible without negativelyimpacting the structural integrity of the components. In addition thediameter of passageway 87 adjacent to outlet 88 may be expanded tofacilitate optimized flow between passageway and outlets.

[0056] The above noted methods to optimize the contact area between thedrive shaft and the grinding cup and standardize components, whereverpractical, regardless of the size of the button to be ground will reducemanufacturing costs and minimize operator exposure to sharp and/orprotruding features when the grinding cup and rotor have engaged. Inaddition, this results in less vibration to reduce rotor wear, as wellas other potential associated wear to the grinding apparatus caused byvibration and/or resonance and improves operational stability,drive/contact surface wear/damage, wear/damage and/or deformation ofelastomeric materials in the drive and/or contact areas by optimizingand harmonizing the forces transferred between the rotor and grindingcup during operation including torsion (rotational) forces, axial (feed)forces and radial (varying side load) forces. Consideration is given tothe size of the grinding cup, the drive means selected, manufacturingcosts, areas required for product identification and necessarystructural strength and/or support in implementation of the presentinvention. The present invention does not require in each case all ofthe possible methods to be employed. Either the drive means and theupper body section or grinding section may be adapted or any combinationthereof.

[0057] The grinding cups of the present invention can be manufactured ingeneral by the same process conventionally used to make grinding cups:by first forming a blank for the body section by machining, casting,forging etc. To accomplish standardization and reduce manufacturingcosts it is desirable to have a standard size of blank. However due thewide range of sizes and profiles of buttons to be ground, it may bepossible to standardize over a range of pre-determined sizes. The blankis pressed into a mould preferably containing a hot diamond/metalmixture. The bottom surface of the blank is heated and bonds to thediamond/metal matrix. Several means of heating and bonding thediamond/metal matrix to the blank are known. Alternatively thediamond/metal matrix can be formed into the grinding section and thenbonded either by a shrink fit and/or with adhesives or solder to ablank.

[0058] The blank for the grinding cup can be machined either before orafter it is pressed into the mould containing the hot diamond/metalmixture. The preferred procedure would be to the extent possiblepre-machine the blank before attaching the grinding matrix section. Inany event some form of post-furnace machining may be required for cleanup purposes. Clean up of the exterior surfaces post-furnace is carriedout by holding the grinding cup in the chuck of a lathe and thenskimming the relevant surfaces wherever needed. At this time it is alsopossible to remove additional material wherever suitable. Post-furnacemachining is used to remove “flash” and other matrix material which mayhave seeped out of the mold during furnacing/pressing.

[0059] Alternative manufacturing methods in order to achieve furtherstandardization, simplify manufacturing, reduce costs and minimizeinventory are within the scope of the present invention.

[0060]FIG. 11 illustrates an adapter 100 according to the presentinvention for attaching a shoulder drive grinding cup as illustrated inFIGS. 3-10 to an output drive shaft employing a hex drive system of thetype illustrated for example in U.S. Pat. Nos. 5,639,237 or 5,727,994.The adapter 100 consists of a holder section 101 and an upper bodysection 102. The holder section 101 and body section 102 are connectedto form an adapter having top and bottom surfaces 103 and 104respectively. The holder section 101 is configured so that the drivemeans of a shoulder drive grinding cup can be inserted into the adapterand driveably engaged. In the illustrated embodiment, the holder section101 is provided with a coaxial passageway or opening 105 extending thelength thereof. An outer portion 106 of the channel 105, extendinginwardly from a free end 107 of the holder section 101, is sized snugly,but slidably, to receive a stem of the grinding cup. Interengaging means108 are provided on the holder section 101 to driveably engage agrinding cup. In the adapter illustrated, the interengaging means 108consists of a diametrically extending slot 109 in the free end 107 ofthe holder section 101. The slot 109 has a top wall 110 and dependingsubstantially parallel side walls 111. The top wall 110 and side walls111 comprise the drive or contact surfaces on the holder section. Agroove 112 in the upper end 113 of passageway 105 is sized to cooperatewith an O-ring on the stem of the grinding cup to help retain thegrinding cup in place during use. The groove 112 is one point ofengagement between the adapter and grinding cup at which forces aretransferred.

[0061] Drive means 114 are provided in the upper body section 102 thatcooperate with the output shaft of the grinding machine. In theembodiment illustrated in FIG. 1l, the body section 102 has a centrallydisposed cavity 115 formed in the top surface 103 of the adapter. Thiscavity 115 is shaped and sized to permit the adapter to be detachablyconnected to the output drive shaft of the grinding machine and rotatedduring the grinding operation. The end portion of the output drive shaftis adapted to fit within the corresponding sized centrally disposedcavity 115 in the top surface 103 of the adapter 100. The output driveshaft is adapted to driveably engage within cavity 115. In the preferredembodiment shown the top portion 116 of cavity 115 in adapter 100 has ahexagonal cross section. To provide support for the grinding cup andminimize vibration generated axial side load on the adapter, the freeend of the output drive shaft is adapted to fit snugly within the bottomportion 117 of cavity 115 in adapter 100. In the embodiment illustrated,both the free end of the output drive shaft and the bottom portion 117of cavity 115 would have a circular cross section slightly smaller indiameter than the hexagonal drive section 116. Other arrangements arepossible, for example the support section of the cavity can be above thedrive section located at the bottom of the cavity or the drive sectioncan be located intermediate two support sections.

[0062] Retaining means are provided on either the output drive shaft orin the adapter or a combination of both to detachably retain the adapter100 so that adapter 100 will not fly off during use but can still beeasily removed or changed after use. For example in the preferredembodiment shown in FIG. 11 a groove 118 is provided in the wall 119 ofcavity 115 into which an O-ring 120 is placed. The O-ring 120 willco-operate with the exterior surface of the output drive shaft to assistin retaining the grinding cup in place during use and reducing vibrationand resonance. Additional O-rings on the output drive shaft willco-operate with the wall 119 of the bottom portion 117 of cavity 115 andO-ring 120 to retain the grinding cup in place during use. These groovesand O-rings are points of engagement which work to optimize the transferof loads between the adapter and the output drive shaft.

[0063] In the embodiment shown, the holder section 101 of the adapter100 is adapted to optimize the engagement or drive surfaces (top surfaceand side walls of cam) on the drive means of the grinding cup with thecorresponding contact surfaces (top wall 110 and side walls 111 of slot109) on the adapter to reduce vibration to thereby reduce rotor wear, aswell as other potential associated wear to the grinding apparatus causedby vibration and/or resonance and to improve operational stability byoptimizing and harmonizing the forces transferred between the rotor andgrinding cup during operation including torsion (rotational) forces,axial (feed) forces and radial (varying side load) forces.

[0064] The slot 109 in adapter 100 is preferably substantially the samesize (height, width and length) as the cam or shoulder on the grindingcup. This optimizes the contact area between the adapter and thegrinding cup resulting in reduced vibration and rotor wear, as well asother potential associated wear to the grinding apparatus caused byvibration and/or resonance. Reduced vibration also improves operationalstability, drive/contact surface wear/damage, wear/damage and/ordeformation of elastomeric materials in the drive and/or contact areasby optimizing and harmonizing the forces transferred between the rotorand grinding cup during operation including torsion (rotational) forces,axial (feed) forces and radial (varying side load) forces. In addition,substantially reducing vibration and/or resonance, minimizes thedeterioration of the preferred built-in profile of the cavity in thegrinding section.

[0065] As noted previously, standardizing components, whereverpractical, regardless of the size of the button to be ground will reducemanufacturing costs and minimize operator exposure to sharp and/orprotruding features when the grinding cup and rotor have engaged. In theembodiment illustrated, the diametrically extending slot 109 at the freeend 107 of the holder section 101 of the adapter 100 is about the samesize as the diameter of the top surface of the upper body section of thegrinding cup. In the adapter illustrated in FIGS. 11, the diameter ofthe body section 102 is reduced by tapering part or all the exteriorsurface 121 of the upper body section to form a beveled portion 122.Alternatively the reduction of the diameter of the exterior surface 121can be radial or form a reverse radius. The beveled portion 122terminates in neck portion 123 that connects to the holder section 101.In the embodiment illustrated in FIG. 11, neck portion 122 is generallycylindrical with a diameter sufficient to provide structural support forthe grinding cup.

[0066]FIG. 12 shows another embodiment of an adapter 130 according tothe present invention. The adapter 130 is similar to the adapter shownin FIG. 11 except that the peripheral edge 131 of the free end 132 ofthe holder section 134 of adapter 130 is rounded or beveled to avoidsharp or protruding edges while improving accessibility to the grindingcup for faster and easier switching to appropriate size and profile ofgrinding cup.

[0067]FIG. 13 illustrates another method of reducing vibration andimproving operational stability, drive/contact surface wear/damage,wear/damage and/or deformation of elastomeric materials in the driveand/or contact areas by optimizing and harmonizing the forcestransferred between the rotor and grinding cup during operationincluding torsion (rotational) forces, axial (feed) forces and radial(varying side load) forces. In the embodiment shown, a grinding cup 140consists of a lower grinding section 141 and an upper body section 142integrally connected to form a grinding cup having top and bottomsurfaces 143 and 144 respectively.

[0068] Drive means 145 are provided on the upper body section 142 thatcooperate with the output drive shaft of the grinding machine. In FIG.13, the drive means 145 consists of a hollow vertical upright stem 146centrally located on the top surface 143 of the grinding cup 140. Cammeans or shoulder 147, is provided at the base of the stem 146 and issized to engage with a diametrically extending slot 28 (FIG. 1) at thefree end 26 of an output drive shaft of the grinding machine. The hollowstem 146 is inserted into the opening 22 in the output drive shaft ofthe grinding machine. Retaining means 148 are provided in conjunctionwith the drive means 145 to releasably secure the grinding cup to theoutput drive shaft of the grinding machine during use. In the preferredembodiment illustrated in FIG. 13, the retaining means 148 are twospaced apart O-rings 149, 150 located in grooves on the stem 146 of thegrinding cup. Optionally the retaining means could also be located onthe drive shaft or a combination of retaining means located on both thegrinding cup and output drive shaft working independently orcooperatively. In the embodiment shown the hollow stem 146 is longerthan the stem shown for the grinding cups of FIGS. 3-10. The combinationof the longer stem and two spaced apart O-rings provides additionalsupport for the grinding cup and further engagement points foroptimizing transfer of loads between the grinding cup and the outputdrive shaft or adapter.

[0069]FIG. 14 illustrates the application of utilizing additionalsupport for the grinding cup and further engagement points foroptimizing transfer of loads between the grinding cup and the outputdrive shaft or adapter. FIG. 14 illustrates an extended adapter 200according to the present invention for attaching a hex drive grindingcup to an output drive shaft employing a hex drive system of the typeillustrated for example in U.S. Pat. Nos. 5,639,237 or 5,727,994. Theadapter 200 consists of a holder section, generally indicated at 201,and body or connector portion generally indicated at 202. The holdersection 201 and connector portion 202 in the embodiment illustrated areconnected to form an adapter having top and bottom surfaces 203 and 204respectively. The holder section 201 is configured so that the endportion 205 of the adapter is adapted to fit within and driveably engagethe corresponding sized centrally disposed cavity in the top surface ofthe grinding cup. In the preferred embodiment shown end portion 205 hasan upper drive section 206 and a lower support section 207. In theembodiment shown the upper drive section 206 has a hexagonal crosssection but other cross-sections are within the scope of the invention.To provide support for the grinding cup and minimize vibration generatedaxial side load on the grinding cup, lower support section 207 of theend portion 205 of the adapter 200 is adapted to fit snugly within thebottom portion of the cavity in the top surface of the grinding cup. Inthe shown embodiment, the lower support section 207 of the adapter 200has a circular cross section slightly smaller in diameter than the upperdrive section 206. While the embodiment shown has an upper drive sectionand lower support section, other arrangements are possible for examplethe support section can be above the drive section or the drive sectioncan be located intermediate two support sections.

[0070] Retaining means are provided on either the adapter or in thegrinding cup to detachably retain the grinding cup so that grinding cupwill not fly off during use but can still be easily removed or changedafter use. In addition, retaining means can be provided by a combinationof both retaining means acting concurrently, cooperatively providingimproved retention. For example in the preferred embodiment shown inFIG. 14 a pair of grooves 208, 209 are provided on the lower supportsection 207 into which O-rings 210 are placed. The O-rings 210 willco-operate with the wall of the support section of the cavity in the topsurface of the grinding cup to assist in retaining the grinding cup inplace during use and reducing vibration and resonance.

[0071] In the illustrated embodiment, the holder section 201 is providedwith a coaxial passageway or opening 211 extending the length thereofand communicating with a corresponding passageway or opening 225 in thebody portion 202.

[0072] Drive means, generally indicated at 214, are provided on or inthe body portion 202 that cooperate with the output shaft of thegrinding machine. In the embodiment illustrated in FIG. 14, the bodyportion 202 has a centrally disposed cavity 215 formed in the topsurface 203 of the adapter. This cavity 215 is shaped and sized topermit the adapter to be detachably connected to the output drive shaftof the grinding machine and rotated during the grinding operation. Theend portion of the output drive shaft is adapted to fit within thecorresponding sized centrally disposed cavity 215 in the top surface 203of the adapter 200. The output drive shaft is adapted to driveablyengage within cavity 215. The cavity 215 has a drive section 216 and oneor more support sections 217. In the preferred embodiment shown thedrive section 216 of cavity 215 in adapter 200 has a hexagonal crosssection and two support sections 217, a lower support section 218 and anupper support section 219 are provided with the drive section 216between said support sections. To provide support for the grinding cupand minimize vibration generated axial side load on the adapter, thefree end of the output drive shaft is adapted to fit snugly within thebottom portion 218 of cavity 215 in adapter 200. In the embodimentillustrated, both the free end of the output drive shaft and the bottomsupport section 218 of cavity 215 would have a circular cross sectionslightly smaller in diameter than the hexagonal drive section 216. Awasher 220 or other elastomeric material is provided at the bottom 221of lower support section 218 of cavity 215 to provide additionalvibration dampening. To provide further support for the grinding cup andminimize vibration generated axial side load on the adapter, a secondupper support section 219 is provided within cavity 215 above the drivesection 216. The output drive shaft is adapted to fit snugly within theupper support section 219 of cavity 215 in adapter 200. In theembodiment illustrated, both the free end of the output drive shaft andthe upper support section 219 of cavity 215 would have a circular crosssection slightly larger in diameter than the drive section 216. Otherarrangements are possible, for example the support section of the cavitycan be above with the drive section located at the bottom of the cavityor the drive section can be located intermediate two support sections asshown.

[0073] Retaining means are provided on either the output drive shaft orin the adapter or a combination of both to detachably retain the adapter200 so that adapter 200 will not fly off during use but can still beeasily removed or changed after use. For example in the preferredembodiment shown in FIG. 14 one or more grooves 226 are provided in thewalls 222, 223 of the lower support section 218 and upper supportsection 219 of cavity 115 into which O-rings 224 are placed. The O-rings224 will co-operate with the exterior surface of the output drive shaftto assist in retaining the grinding cup in place during use and reducingvibration and resonance. Additional O-rings can be provided on theoutput drive shaft to co-operate with the wall 222 of the bottom supportsection 218 of cavity 215 and O-rings 224 to retain the grinding cup inplace during use. These grooves and O-rings are points of engagementwhich work to optimize the transfer of loads between the adapter and theoutput drive shaft.

[0074] The principles of the present invention can be applied to alltypes of grinding cups including those illustrated in U.S. Pat. Nos.5,639,237 and 5,727,994. FIG. 15 illustrates another method of reducingvibration and improving operational stability, drive/contact surfacewear/damage, wear/damage and/or deformation of elastomeric materials inthe drive and/or contact areas by optimizing and harmonizing the forcestransferred between the rotor and grinding cup (intended for use withgrinders as illustrated in these two patents) during operation includingtorsion (rotational) forces, axial (feed) forces and radial (varyingside load) forces. In the embodiment shown, a grinding cup, generallyindicated at 300, consists of a lower grinding section 301 and an upperbody section 302 connected to form a grinding cup having top and bottomsurfaces 303 and 304 respectively. The grinding section 301 is formedfrom a material capable of grinding the tungsten carbide button bits. Inthe preferred embodiment, the grinding section is formed from a metaland diamond matrix. The peripheral edge 305 in the bottom surface 304 ispreferably beveled to facilitate the removal of steel from the face ofthe bit around the base of the button during grinding. A centrallydisposed convex recess 306 is formed in the bottom surface 304 havingthe desired profile for the button to be ground.

[0075] Drive means 307 are provided in the upper body section 302 thatcooperate with the output shaft of the grinding machine. In theembodiment illustrated in FIG. 15, the upper body section 302 has acentrally disposed cavity 308 formed in the top surface 303 of thegrinding cup. This cavity 308 is shaped and sized to permit the grindingcup to be detachably connected to the output drive shaft of the grindingmachine or an adapter and rotated during the grinding operation.

[0076] The end portion of the output drive shaft is adapted to fitwithin the corresponding sized centrally disposed cavity 308 in the topsurface 303 of the grinding cup 300. The cavity 308 is provided with adrive section 309 and one or more support sections 310. The output driveshaft is adapted to driveably engage within the drive section 309 ofcavity 308. In the preferred embodiment shown the drive section 309 ofcavity 308 in grinding cup 300 has a hexagonal cross section. In theembodiment illustrated, cavity 308 has two support sections 310: anupper support section 311 and a lower support section 312 with drivesection 309 between the support sections. To provide support for thegrinding cup and minimize vibration generated axial side load on thegrinding cup, the free end of the output drive shaft is adapted to fitsnugly within the lower support section 312 of cavity 308 in grindingcup 300. In the shown embodiment, both the free end of the output driveshaft and the lower support section 312 of cavity 308 have a circularcross section slightly smaller in diameter than the drive section 309.Other arrangements are possible for example the support sections of thecavity can both be above the drive section with the drive sectionlocated at the bottom of the cavity or vice versa or the drive sectioncan be located intermediate two support sections as shown.

[0077] Means are provided in said cavity in the top surface of saidgrinding cup to reduce vibration and improve operational stability,drive/contact surface wear/damage, wear/damage and/or deformation ofelastomeric materials in the drive and/or contact areas by optimizingand harmonizing the forces transferred between the rotor and grindingcup during operation including torsion (rotational) forces, axial (feed)forces and radial (varying side load) forces. In the embodimentillustrated retaining means are provided on either the output driveshaft or in the grinding cup to detachably retain the grinding cup 300so that grinding cup 300 will not fly off during use but can still beeasily removed or changed after use and reduce vibration, improvestability and reduce wear and damage. In addition, retaining means canbe provided by a combination of both retaining means actingconcurrently, cooperatively providing improved retention, reducedvibration, improved stability and reduced wear and damage. For examplein the preferred embodiment shown in FIG. 15 grooves 314, 315 areprovided in the walls 316, 317 of the lower support section 312 andupper support section 311 of cavity 308 into which O-rings 318 areplaced. The O-rings 318 will co-operate with the exterior surface of theoutput drive shaft to assist in retaining the grinding cup in placeduring use and reducing vibration and resonance. Additional O-rings onthe output drive shaft will co-operate with the wall 315 of the lowersupport section 312 of cavity 308 and O-ring 318 to retain the grindingcup in place during use. To further reduce vibration, improve stabilityand reduce wear and damage it is possible to utilize lighter weightmaterials such as elastomeric materials in the upper body section of thegrinding cup or to form part of the drive means or retaining means.

[0078] One or more passageways 321 connect cavity 308 with the recess306 in the grinding section to permit a coolant, preferably water,optionally mixed with cutting oil or a water/air mist, to be provided tothe surface of the button during grinding, through outlets 322. As shownin The drive means 307, upper body section 302 and grinding section 301of the grinding cup 300 are adapted to reduce vibration and improveoperational stability, drive/contact surface wear/damage, wear/damageand/or deformation of elastomeric materials in the drive and/or contactareas by optimizing and harmonizing the forces transferred between therotor and grinding cup during operation including torsion (rotational)forces, axial (feed) forces and radial (varying side load) forces. Thecombination of the two support sections and two spaced apart O-ringsprovides additional support for the grinding cup and further engagementpoints for optimizing transfer of loads between the grinding cup and theoutput drive shaft or adapter.

[0079] To further reduce vibration and improve operational stability,drive/contact surface wear/damage, wear/damage and/or deformation ofelastomeric materials in the drive and/or contact areas by optimizingand harmonizing the forces transferred between the rotor and grindingcup during operation including torsion (rotational) forces, axial (feed)forces and radial (varying side load) forces, it is possible to utilizelighter weight materials such as elastomeric materials in the upper bodysection of the grinding cup or to form part of the drive means orretaining means.

[0080] Having illustrated and described a preferred embodiment of theinvention and certain possible modifications thereto, it should beapparent to those of ordinary skill in the art that the inventionpermits of further modification in arrangement and detail. For examplethe grinding cup may include an adapter to connect the grinding cup ofone drive system to the output drive shaft of a different drive system.The invention is applicable to optimizing the engagement or drivesurfaces between the drive shaft and the adapter as well as the adapterand the grinding cup.

[0081] It will be appreciated that the above description related to thepreferred embodiment by way of example only. Many variations on theinvention will be obvious to those knowledgeable in the field, and suchobvious variations are within the scope of the invention as describedand claimed, whether or not expressly described.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A grinding cup forgrinding the hard metal inserts or working tips of drill bits(percussive or rotary), tunnel boring machine cutters (TBM) and raisedbore machine cutters (RBM) to restore them to substantially theiroriginal profile, said grinding cups having a lower grinding section andan upper body section connected to form a grinding cup having top andbottom surfaces, a centrally disposed convex recess formed in the bottomsurface having the desired profile to be ground, one or more passagewaysin the upper body section and grinding section to permit a coolant to beprovided to one or more outlets on the bottom surface, drive meansprovided on or in the upper body section that cooperates with the outputshaft of a grinding machine, retaining means provided in conjunctionwith the drive means for detachable connection of the grinding cup to anoutput shaft of the grinding machine during use wherein the drive meansand the upper body section or grinding section of the grinding cup areadapted to optimize the engagement surfaces and points of contact,directly or indirectly, between the drive shaft and the grinding cup toreduce negative impact on operational stability and rotor wear and wearto the grinding apparatus caused by vibration and resonance.
 2. Agrinding cup according to claim 1 wherein the drive means has engagementsurfaces sized and shaped to substantially match contact areas on theoutput drive shaft of the grinding machine or any adapter connectingsaid grinding cup to the output drive shaft.
 3. A grinding cup accordingto claims 1 or 2 wherein the drive or contact areas between the grindingcup and the output shaft of the grinding machine or adapter containmaterials suitable for reducing vibration and wear or damage duringoperation.
 4. A grinding cup according to any of claims 1, 2 or 3wherein the mass of the grinding cup is reduced by incorporating lighterweight materials in one or more of the upper body section, the drivemeans or retaining means.
 5. A grinding cup according to claim 4 whereinthe lighter weight material incorporated to reduce the mass of thegrinding cup is an elastomeric material.
 6. A grinding cup according toany one of claims 1 to 5 wherein the drive means consists of a hollowvertical upright stem centrally located an the top surface of thegrinding cup.
 7. A grinding cup according to claim 6 wherein cam meansare provided at the base of the stem sized to engage with adiametrically extending recess at the free end of a hollow drive shaftof the grinding machine.
 8. A grinding cup according to claim 6 or 7wherein the retaining means consists of two or more spaced apart O-ringslocated on the hollow vertical upright stem to provide support for thegrinding cup and additional engagement points for optimizing transfer ofloads between the grinding cup and the output drive shaft or adapter. 9.A grinding cup according to claim 9 wherein said hollow vertical uprightstem is extended.
 10. A grinding cup according to any one of claims 1 to5 wherein the drive means consists of a centrally disposed cavity formedin the top surface of the grinding cup, said cavity shaped and sized topermit the grinding cup to be detachably connected directly Orindirectly by an adapter to the output drive shaft of the grindingmachine and rotated during the grinding operation wherein an end portionof the output drive shaft or adapter is adapted to fit within thecorresponding sized centrally disposed cavity and driveably engagewithin said cavity, said cavity having a drive section and one or moresupport sections.
 11. A grinding cup according to claims 10 wherein theretaining means consists of two or more spaced apart O-rings located inthe support sections of the centrally disposed cavity formed in the topsurface of the grinding cup to provide support for the grinding cup andadditional engagement points for optimizing transfer of loads betweenthe grinding cup and the output drive shaft or adapter.
 12. A grindingcup according to claim 11 wherein there are two support sections in saidcavity on either side of said drive section.
 13. A grinding cupaccording to any one of claims 1 to 12 wherein the diameter of the bodysection is reduced by tapering part or all the exterior surface to forma beveled portion said beveled portion terminating in a neck portionthat connects to the grinding section.
 14. A grinding cup according toany one of claims 1 to 13 wherein the peripheral surface of the metalportion of said grinding section is machined to the point of connectionwith the upper body section in a profile corresponding to centrallydisposed convex recess.
 15. A grinding cup according to any one ofclaims 1 to 14 wherein the diameter of the passageways through the upperbody section and grinding section are increased as wide as possiblewithout negatively impacting the structural integrity of the grindingcup.
 16. An adapter for attaching a grinding cup according to claim 1having drive means of one type to an output drive shaft of a grindingmachine employing a different drive system, said adapter consisting of aholder section S and an upper body section, said holder section and saidbody section connected to form an adapter having top and bottom surfaceswherein said holder section is configured so that the drive means of thegrinding cup can be inserted into or onto the adapter and driveablyengaged, said holder section adapted to optimize the engagement surfacesand points of contact between the adapter and the grinding cup to reducenegative impact on operational stability and rotor wear and wear to thegrinding apparatus caused by vibration and/or resonance and whereindrive means are provided on the upper body section that cooperate withthe output shaft of the grinding machine and retaining means areprovided on either the output drive shaft or on the drive means of theupper body section of said adapter or a combination of both todetachably retain the adapter so that adapter will not fly off duringuse but can still be easily removed or changed after use the upper bodysection of the adapter being adapted to optimize the engagement surfacesand points of contact between the drive shaft and the adapter to reducenegative impact on operational stability and rotor wear and wear to thegrinding apparatus caused by vibration and/or resonance.
 17. An adapteraccording to claim 16 wherein the drive or contact areas between thegrinding cup and adapter or adapter and the output shaft of the grindingmachine contain materials suitable for reducing vibration and wear ordamage during operation.